- Turkish Journal of Biology
- Vol: 25 Issue: 3
- Production of Ethanol from Beet Molasses by Ca-Alginate Immobilized Yeast Cells in a Packed-Bed Bior...
Production of Ethanol from Beet Molasses by Ca-Alginate Immobilized Yeast Cells in a Packed-Bed Bioreactor
Authors : Yekta Göksungur, Neşe Zorlu
Pages : 265-275
View : 8 | Download : 4
Publication Date : 9999-12-31
Article Type : Makaleler
Abstract :The continuous production of ethanol from beet molasses by Ca-alginate immobilized Saccharomyces cerevisiae in a packed-bed bioreactor was investigated. The temperature was maintained at 30°C and the dilution rate was 0.22 h-1. Maximum ethanol (4.62%), theoretical yield (82.9%) and volumetric productivity (10.16 gl-1h-1) were obtained from the beet molasses medium containing 10.90% total sugar with 2.0-2.4 mm diameter beads prepared from 2% (w/v) sodium alginate solution. At higher substrate concentrations, substrate was recirculated through the packed-bed bioreactor to increase yields and to decrease residual sugar content. The bioreactor system was operated at a constant dilution rate of 0.22 h-1 for 25 days without loss of original fermentation capacity. Compared to packed-bed bioreactor, lower ethanol concentration (3.94%), theoretical yield (70.7%) and productivity (8.67 gl-1h-1 ) were obtained in the continuous stirred bioreactor.Keywords : ethanol, beet molasses, calcium alginate, immobilization, packed-bed bioreactor